Activated bleaching composition



United States Patent Ofitice 3349335 Patented Oct. 24, 1967 3,349,035 ACTKVATED BLEACHING COMPOSITIQN Karl Dithmar and Peter Kohliscliek, Frankfurt am Main,

Germany, assignors to Deutsche Goldund Silber-Scheideanstalt vormals Roessler, Frankfurt am Main, Germany No Drawing. Filed May 10, 1965, Ser. No. 454,655

Claims priority, application Germany, May 12, 1964 7 Claims. (Cl. 252-99) ABSTRACT OF THE DISCLOSURE Solid stable bleaching compositions consisting essentially of a solid, stable inorganic peroxygen compound and a 1-substituted-3-acylhydantoin activator of the structure:

wherein R is a member selected from the group consisting of alkyl, cy-cloalkyl, aryl, alkaryl and aralkyl groups and R is an acetyl group, the amount of said activator being about 0.3 to 1.25 mol per mol of peroxygen present.

The invention relates to an agent for treating textiles comprising an active oxygen containing washing agent, such as an inorganic persalt as, for example, perborates, percarbonates, perphosphates or peroxides, containing an activator in the form of an acyl derivative of a hydantoin or its substituted derivatives. Specifically, the activators according to the invention consist of derivatives of hydantoins which have high stability during storage in admixture with such washing agents in addition to having desired activating effect.

Textile fiber materials and commodities produced therefrom are washed as a rule, especially, if they are plant fibers, as cotton or linen, by intimately contracting the materials in a washing solution or bath containing the customary washing agents, as, for example, soaps, detergents or synthetic agents, and containing alkalis, water glass, phosphates, peroxide compounds or mixed wash solutions at room temperature. Or, such solutions, at moderately elevated temperatures may be heated slowly to boiling temperature and held at this temperature for a time. This customary boiling process is not only troublesome and costly, but is also combined with risk of damage to the fibers, especially if it is used for cleaning and/or bleaching pieces of wash, which consist partially or entirely of sensitive fiber materials, such as artificial silk, staple rayon or completely synthetic fibers. Boiling or near boiling wash and bleaching baths, apart from high heat expenditure, also have the disadvantage of being used little for washing machines.

Attempts have already been made to carry out the washing process at temperatures below boiling, but without achieving satisfactory results. It has been demonstrated that the optimum purification or cleaning effect of customary washing agents on cellulose fibers arises initially at or in the vicinity of the boiling point. If the operation is carried out at lower temperatures, only incomplete and unsatisfactory purification and cleaning is achieved.

A commercially available self acting washing agent which contains known peroxide compounds, as sodium perborate, employed for washing, if a temperature lower than close to boiling temperature, for example, a temperature of 60 to C., is used, produces insuflicient and unsatisfactory bleaching because the commercially available perborate compositions are stabilized mostly such that they do not give olf active oxygen in the fiber material at a sufiicient rate until at high or near boiling temperatures.

Accordingly activators have already been proposed which permit washing and bleaching with peroxide compounds, for example, in the form of perborates, percarbonates, perphosphates or peroxides, in wash and bleach ing solutions at lower temperatures and thereby produce a good whitening efiect as well as satisfactory spot removal. For example, formamide, amides of unsaturated lower carboxylic acids, nitriles, anhydrides of mono or polybasic carboxylic acids and anhydrides of unsaturated carboxylic acids are known activators. Acylated phosphoric acid esters have also been suggested.

Acyl derivatives of hydantoins and substituted hydantoins, for example, 5,5-dimethyl hydantoins, have also been suggested as activators for peroxide compounds in wash and bleaching baths. Hydantoin or the substituted hydantoins can be acylated at one or both secondary amino groups. They provide a strong increase in brightening or bleaching etfect and permit the wash and bleaching temperature, maintained at to C. in the usual hot wash heretofore, to be maintained at a lower value while providing the same increase in whiteness and spot removal.

Development of the use of such activators has naturally enlarged knowledge of their activating action and suggested from various sides difierent types of compounds for reducing the wash temperature. For one reason or another these have not been carried into practice heretofore due to specific inherent disadvantanges in the compositions produced therewith.

Advances can be achieved with acylamido compounds. The acyl groups of the amido compounds have short chain length or are derived from aryl carboxylic acids having very simple structure, as, for example, benzoic acid, since these groups react more favorably than acid groups having higher molecular weight. It has, however, already been observed that amido compounds having a benzoyl group react more gradually than such compounds having an acetyl group. It is therefore desirable to use compounds which have both the stability of benzoylamido compounds and the economy or cheapness of acetylamido compounds. In mass production, as in mass production of wash powders, only the most suitable and economical products have a chance of being used. Therefore it was clear that the costly benzoyl group should be replaced by the cheaper acetyl group.

It was also thought that the increased activity of the short chain acyl groups was utilized most effectively by grouping the acyl groups wherein more than one acyl group was present in such compounds. There was no increased activity demonstrated therewith however. Moreover, the compounds of this type are unstable and give off acid groups when stored for a relatively short time. For example, when N,N-diacetyl-5,5-dimethyl hydantoin and N-monoacetyl-5,5-dimethyl hydantoin, which have similar molecular structure, are compared with regard to storage stability, the monoacetyl compound is essentially more stable and moreover is at least as active as the diacetyl compound.

A test has been tried wherein the reactivity of the acyl groups is valuated by the gradual release of iodine from potassium iodide which provides indicia of suitable acylamido compounds. Compounds, according to this test, which release the largest minimum amount of iodine in a given unit of time are suitable. It has been determined through research, however, that a series of compounds which are known to be reactive are not suitable as activators, even though the wash temperature employing peroxide containing washing agents can be lowered with such compounds. They decompose and when stored for a long time in admixture with components contained in customary wash powders, such as sodium perborate, sodium tripolyphosphate, sodium pyrophosphate or silicates, are unstable. The reaction, which enables reduction of the wash temperature, comprising separation of the acyl groups and their conversion with hydrogen peroxide of the sodium perborate to monoperoxy acid, proceeds at room temperature, significantly recognizable in some cases by the smell of acetic acid. This emanates from the substances at normal temperatures.

Acylamides must not only have acyl groups which are reactive and mobile to be usable as peroxygen activators for wash powders. They must also satisfy a second prerequisite requirement if such additives are to be practically usable. They must have more storage stability in intimate mixtures containing the above major constituents of customary peroxygen washing agents than those compounds employed heretofore. Known acyl compounds have not satisfied the two requirements, specifically the second requirement, because they lose their effectiveness in mixtures containing the wash powders during storage.

The invention accordingly comprises an agent for treating textiles which contains an active oxygen evolving washing agent, such as inorganic persalts, as, for example, perborates, percarbonates, perphosphates or peroxides and agents usually employed in washing and bleaching processes, as well as an activator in the form of an acyl derivative of a hydantoin or their substituted compounds, wherein the activator is a hydantoin compound having both increased activating effectiveness and also optimum storage capability.

The activators according to the invention are l-substituted hydantoins represented by the structure wherein R in the 1 position, is an alkyl, e.g., lower alkyl, cycloalkyl, aryl, alkaryl or aralkyl group and R in the 3 position, is preferably an acetyl group.

These monoacetyl hydantoins in contrast to known materials, such as, N,N-diacetyl-5,5-dimethyl hydantoin, are not substituted in the 5 position, e.g., with a methyl group. Only these specific hydantoin compounds according to the invention have both high activating eifect and high stability during storage. The substituents given above in the 1 position increase stability during storage while substituents in the 5 position reduce stability during storage. Another advantage of the N-monoacetyl hydantoins which are not substituted in the 5 position is that they have smaller molecular weight and therewith higher effectiveness in addition to being cheaper to produce.

The compounds according to the invention do not de compose at room temperature in a powder mixture containing sodium perborate, sodium tripolyphosphate, sodium pyrophosphate and dry water glass and do not react until the powder mixture is dissolved and, if necessary, heated to medium wash temperature, e.g., 30 to 60 C. When dissolved and employed in peroxide washing agent solutions, the compounds of the invention effectively increase the bleaching effect of such solutions. The compounds containing an acetyl group are cheaper than similar compounds containing a benzoyl group and accordingly have an advantage over known benzoylamides.

The activating agents according to the invention satisfy the prerequisite of effectiveness by releasing the acyl group which reacts with H 0 to form monoperoxy acid when the agents are dissolved in the washing process, as well as the prerequisite of stability during storage at normal temperatures, and accordingly are satisfactory as a commercial, dry powder in admixture with customary auxiliary washing agents, although such washing agents are packed in paper packages or boxes which permit atmospheric moisture to come in contact with the powder.

These prerequisites are satisfied by acyl derivatives of hydantoins as the activating agents wherein an alkyl or aryl group is substituted in the 1 position, not in the 5 position as in known activators, and an acyl group is present in the 3 position. Initially this controlled substitution, i.e., substitution in the 1 and 3 position, enables use of the cheap acetyl group. If the acyl group is present in the 1 position, the compounds do not have satisfactory reactivity for reacting with H 0 in aqueous solution to increase the bleaching potential.

The quantity of activator employed in the compositions and process according to the invention depends on the active oxygen content of the washing or bleaching composition in the baths prepared therefrom. It also depends on the degree of bleaching required and the individual persalt employed. Good results are obtained when 0.3 to 1.25 mol of activator are provided per mol of peroxygen present. For example, 0.0015 to 0.0046 mol per liter of activator can be successfully used in a bath containing 0.004 mol per liter of sodium perborate.

It is desirable to employ a bleaching bath which has a 'pH of about 6.0 to 10.0.

The compounds and process of the invention are further described in the following examples. The advantages of these materials in washing and bleaching agents are evident from the tables accompanying the examples.

EXAMPLE 1 This example illustrates the stability during storage of the compositions of the invention.

The following wash powder composition was compounded containing sodium perborate, phosphates, silicate and 1-phenyl-3-acetyl hydantoin in the following ratio by weight:

The mixture was stored for a year and tested for remaining active oxygen content and decomposition after about one month. Three times during this period tests were run to determine how Well a washing bath prepared from this mixture could remove red wine stain from staple rayon fabric in comparison to a corresponding wash bath without added acylated hydantoins.

Table 1 gives the amount of active oxygen still present employing a dosage of the above washing agent of 4.45 g. per liter of water when the mixture was titrated with a potassium permanganate solution.

Table 1 Amount of active Time tested: oxygen in grams Starting material Q. 0.063 after 1 month 0.062 after 2 months Q 0.062 after 3 months 0.062 after 4 months 0.062 after 5 months 0.062 after 6 months 0.061 after 7 months 0.061 after 8 months 0.059 after 9 months 0.059 after 10 months 0.059 after 11 months 0.058

after 12 months 0.058

EXAMPLE 2 This example illustrates the effectiveness of the compositions of the invention in removing strong red wine stain.

A piece of staple rayon fabric was boiled for an hour in red wine and then washed three consecutive times for 15 minutes with a wash solution containing 4.45 g. per liter of the wash powder described in Example I at 60 C. Subsequently the increase in brightness of the fabric was measured on a Zeiss-Elrepho whiteness measurer using a white standard 565 and filter 6. A piece of staple rayon fabric was soiled or stained in a like manner and washed in the same Way in a wash solution containing the same wash powder without the addition of 1-phenyl-3-acetyl hydantoin. The following results were obtained on the day the washing compositions were made up:

Percent (a) Whiteness of textile after staining with red wine before washing 32.0 (b) Whiteness of textile after staining with red wine and subsequent Washing at 60 C. with washing agent containing activator 62.1

(c) Whiteness of textile after staining with red wine with subsequent washing at 60 C. with the same Washing agent as employed in (b) but without added activator 43.9 (d) Difference in degree of Whiteness of textiles, stained .with red wine washed with and without an activator 18.2

without added activator 43.1 (d) Difference in degree of whiteness of textiles Nvashed with and without an activator 17.0

The difference in degree of whiteness after nine months was reduced from 18 to 17%, a reduction of only 1%, which is practically an insignificant loss. This demonstrates that 1-phenyl-3-acyl hydantoins in admixture with components of a washing agent are not changed by storage.

Other activators proved effective in removing red wine stains are 1-alkaryl-3-acetyl hydantoins set out in following Examples 3, 4 and 5 employing a washing composition and bath according to Example 1. These activato-rs are likewise effective in increasing the bleaching effect.

EXAMPLE 3 A washing composition was prepared as in Example 1 employing 1-o-tolyl-3-acet-yl hydantoin, having a melting point of 122l23 C., as the activator. Employing the initial staining and washing procedures of Example 2 the following results were obtained:

Percent (a) Degree of whiteness before Washing 33.5 (b) Degree of whiteness after washing without activator 49.4

(0) Degree of whiteness after washing with activator 68.2

Difference in degree of whiteness 18.8

An increase in degree of brightness of about 18.8% is obtained by the addition of the activator.

EXAMPLE 4 A washing composition was prepared as in Example 1 employing 1-m-tolyl-3-acetyl hydantoin, having a melting point of 112-113 C., as the activator. Employing the initial washing and staining procedure of Example 2 the following results wer obtained:

Percent (a) Degree of Whiteness before washing 33.5 V (b) Degree pf whiteness aften. washing without activator 49.4 (c) Degree of whiteness after Washing with activator 66.4 Difference in degree of whiteness 17.0

An increase in degree of brightness of about 17.0% is obtained by the addition of the activator.

EXAMPLE 5 A washing composition was prepared as in Example 1 employing l-p-tolyl-B-acetyl hydantoin, having a melting point of -170 C., as the activator. Employing the initial staining and washing procedure of Example 2 the following results wer obtained:

Percent (a) Degree of whiteness before washing 33.5 (b) Degree of whiteness after washing without activator 43.6 (0) Degree of whiteness after washing with activator 63.9

Difference in degree of whiteness 17.6

EXAMPLE 6 1-cyclohexyl-3-acetyl hydantoin, as an example of a suitable 1-cycloalkyl-3-acetyl hydantoin, was prepared, as described for all of the acetyl hydantoins of the invention which are unsubstituted in the 5 position, by acylating the corresponding hydantoin with acetic acid anhydride. Carbon-hydrogen-nitrogen determination showed good agreement with calculated values:

Found: C, 59.10%; H, 7.30%; N, 12.56%. Calculated: C, 58.91%; H, 7.19%; N, 12.40%.

It was concluded therefrom that the compound produced having a melting point of 86-87" C. was l-cyclohexyl-3-acetyl hydantoin.

A washing composition was prepared as in Example 1 employing this compound as the activator. Employing the initial staining and washing procedures of Example 2 the following results were obtained:

Percent (a) Degree of whiteness before washing 37.1 (b) Degree of whiteness after washing without activator 44.7 (c) Degree of whiteness after washing with activator 64.2

Difference in degree of whiteness 19.5

All measurements of degree of whiteness were carried out on a Zeiss-Elrepho measurer using a White standard 565 and filter 6.

Washing agent solutions containing the activators according to the invention demonstrated increased spot removal and bleaching effect even after the wash powders used therefor containing the activators were stored for one year. The increase in degree of whiteness achieved with the activators was about 17%. Such increases in bleaching eflect can be achieved, as tests have demonstrated, with a 30 higher wash temperature, e.g., 90 C. instead of 60 C. The activating agents of the invention are preferably water soluble.

We claim:

1. A solid, stable bleaching composition for the production of aqueous baths having a bleaching action consisting essentially of a solid, stable inorganic peroxygen bleaching compound and a 1-substituted-3 acylhydantoin activator of the structure:

wherein R is a member selected from the group consisting of alkyl, cycloalkyl, phenyl, alkyl-phenyl and phenylal kyl, the alkyl groups indicated being lower alkyl and R is an acetyl group, the amount of said activator being about 0.3 to 1.125 mol per mol of peroXygen present.

2. A bleaching composition as in claim 1 wherein the activator is 1-phenyl-3-acetylhydantoin.

3. A bleaching composition as in claim 1 wherein the activator is 1-o-tolyl-3-a-cetylhydantoin.

4. A bleaching composition as in claim 1 wherein the activator is 1-m-tolyl-3-acetylhydantoin.

5. A bleaching composition as in claim 1 wherein the activator is 1-p-tolyl-3-acetylhydantoin.

6. A bleaching composition as in claim 1 wherein the activator is 1-cyclohexyl-3-acety1hyd antoin.

7. A solid, stable bleaching composition consisting essentially of about 18 parts by Weight sodium perborate, about 30 parts by weight 1-phenyl-3-acetylhydantoin, about 10.50 parts by weight dry Water glass, about 18.75 parts by weight sodium tripolyphosphate, about 18.75 parts by weight sodium pyrophosphate, and about 37.5 parts by weight tetrapropylene benzylsulfonate.

References Cited UNITED STATES PATENTS 'LEON D. ROSDOL, Primary Examiner.

M. WEINBLA'IT, Assistant Examiner. 

1. A SOLID, STABLE BLEACHING COMPOSITION FOR THE PRODUCTION OF AQUEOUS BATHS HAVING A BLEACHING ACTION CONSISTING ESSENTIALLY OF A SOLID, STABLE INORGANIC PEROXYGEN BLEACHING COMPOUND AND A 1-SUBSTITUTED-3-ACYLHYDANTOIN ACTIVATOR OF THE STRUCTURE: 1-R1,2,4-DI(O=),3-R2-IMIDAZOLIDENE WHEREIN R1 IS A MEMBER SELECTED FROM THE GROUND CONSISTING OF ALKYL, CYCLOALKYL, PHENYL, ALKYL-PHENYL AND PHENYLALKYL, THE ALKYL GROUPS INDICATED BELOW LOWER ALKYL AND R2 IS AN ACETYL GROUP, THE AMOUNT OF SAID ACTIVATOR BEING ABOUT 0.3 TO 1.25 MOL PER MOL OF PEROXYGEN PRESENT. 